Wavefront LASIK Surgery – How it Differs From Conventional LASIK
First, what’s in common?
Wavefront LASIK (also called Custom LASIK), and traditional LASIK both:
· Use an excimer laser
· Create a tiny flap on the corneal surface to expose the underlying tissue to be worked on
· Modify the shape of the cornea by vaporizing tiny pieces that were impairing your vision
· Are extremely precise
Advantages of Wavefront (Custom) LASIK
It provides particularly precise information on how your vision is impaired. Custom LASIK measures each eye with a special laser, using wavefront technology, and creates a 3-D map of the eye. This is translated by the Wavefront system into mathematical information that’s used to guide the laser in correcting the problems.
Two types of vision problems
1. Lower order aberrations – nearsightedness, farsightedness and astigmatism.
These are refractive errors and are correctable by traditional LASIK surgery.
2. Higher order aberrations (HOA) – halos around lights, impaired night vision, starbursts etc.
These are not refractive errors and not correctable by traditional LASIK, but can be measured and corrected by Wavefront LASIK.
The HOAs are sometimes created by traditional LASIK, and although there are still some who argue that Wavefront LASIK can also create them, most refractive surgeons agree that it’s much less likely to create them than traditional LASIK.
About 75% of refractive surgeons now use Custom LASIK.
Amount vs. quality of vision
Amount – A person with 20/20 vision is said to have perfect eyesight. That’s an assessment of the person’s AMOUNT of vision, or how MUCH he sees. Impairment of our amount of vision is brought about by lower order aberrations.
Quality – How WELL we see is determined by the presence or absence of higher order aberrations. So if we have impaired contrast sensitivity and can’t see very well at night, or we have glare and halos around lights, these defects can be both measured and treated by Wavefront LASIK.
The Wavefront LASIK procedure
· The eye surgeon sends a light ray into your eye
The light is reflected back off the retina (interior surface of the back of the eye, like the film in a camera) to the Wavefront system
· The system arranges this modified light into a pattern of all your vision aberrations, lower and higher
· It displays this pattern on its computer monitor as a 3-D map of each eye, the wavefront map
· When your eye surgeon applies the laser treatment to your eyes, he uses this same information to guide the laser.
Unique to you
This all results in a vision remedy that’s unique to you. Unlike glasses and contact lenses, which are remedies that come according to prescriptions that millions of other people also have, this treatment is entirely customized. That’s another way of saying that it’s extremely precise, so precise that nobody else would benefit from it. They’d all have their own 3-D maps.
Pre-testing with traditional LASIK
Before traditional LASIK, there are also tests done to pinpoint the corneal problems.
They’re done using a variety of devices which each give a different kind of information. For example:
· The photopter – you look through various pairs of lenses and tell the eye doctor which set gives you the best clarity
· The corneal topographer – collects reflected infra-red light from your eyes and creates a digital map of each eye
· Fluoracaine or some similar dye – stains the corneal surface so that your eye doctor can see more clearly where the irregularities are
These tests give a lot of information, but not to the precise detail of the wavefront technology. They also take longer.
If you’re considering a LASIK procedure, whether LASEK, PRK, or Epi-Lasik, or traditional LASIK, you can have a wavefront diagnostic done first. This will indicate the severity of any HOAs you may have. This information in turn will guide your eye surgeon in recommending the best procedure for you.